This invention relates generally to apparatus for handling generally flat circular articles, such as plastic lids and, more particularly, to a spin bar for use therein having two sections, each of which rotates at a different speed.
Plastic lid handling systems are known in the prior art, representative of which are those described in U.S. Pat. Nos. 5,863,177; 6,547,057; and 6,662,928. In such systems, plastic lids move along a conveyor in a single file, horizontally oriented. The conveyor terminates in a waterfall section, over which the lids sequentially drop in order to reorient them to a vertical on-edge position. They drop onto a pair of parallel cylindrical bars, rotating at the same speed, to maintain the vertical orientation of the lids. The rotating cylindrical bars, known as spin bars, are longitudinally angled slightly downwardly to facilitate collection of the lids in a stack at the discharge end of the spin bars. It has been discovered that rotation of both spin bars at the same speed, in accordance with these prior art lid handling system, impedes travel of the vertically oriented lids along the length of the spin bars.
It would therefore be advantageous to provide a lid handling system that stabilizes the lids as they drop off the waterfall end of the conveyor to become vertically oriented and that then promotes lateral movement of the vertically oriented lids into a stack for collection.
In accordance with the illustrated preferred embodiment of the present invention, one of a pair of parallel rotating spin bars is split into a shorter lid entry section and a longer lid discharge section. The shorter lid entry section rotates at the same speed as the other one of the parallel spin bars to stabilize the lids as they drop off the waterfall end of the conveyor to become vertically on-edge oriented, while the longer discharge section of the split spin bar rotates at a different speed to promote lateral movement of the vertically oriented lids along the spin bars into a stack at the discharge end thereof.